// Loaded from https://dev.jspm.io/npm:pako@1.0.11/lib/zlib/trees.dew.js


import { dew as _commonDewDew } from "../utils/common.dew.js";
var exports = {},
    _dewExec = false;
export function dew() {
  if (_dewExec) return exports;
  _dewExec = true;

  // (C) 1995-2013 Jean-loup Gailly and Mark Adler
  // (C) 2014-2017 Vitaly Puzrin and Andrey Tupitsin
  //
  // This software is provided 'as-is', without any express or implied
  // warranty. In no event will the authors be held liable for any damages
  // arising from the use of this software.
  //
  // Permission is granted to anyone to use this software for any purpose,
  // including commercial applications, and to alter it and redistribute it
  // freely, subject to the following restrictions:
  //
  // 1. The origin of this software must not be misrepresented; you must not
  //   claim that you wrote the original software. If you use this software
  //   in a product, an acknowledgment in the product documentation would be
  //   appreciated but is not required.
  // 2. Altered source versions must be plainly marked as such, and must not be
  //   misrepresented as being the original software.
  // 3. This notice may not be removed or altered from any source distribution.

  /* eslint-disable space-unary-ops */
  var utils = _commonDewDew();
  /* Public constants ==========================================================*/

  /* ===========================================================================*/
  //var Z_FILTERED          = 1;
  //var Z_HUFFMAN_ONLY      = 2;
  //var Z_RLE               = 3;


  var Z_FIXED = 4; //var Z_DEFAULT_STRATEGY  = 0;

  /* Possible values of the data_type field (though see inflate()) */

  var Z_BINARY = 0;
  var Z_TEXT = 1; //var Z_ASCII             = 1; // = Z_TEXT

  var Z_UNKNOWN = 2;
  /*============================================================================*/

  function zero(buf) {
    var len = buf.length;

    while (--len >= 0) {
      buf[len] = 0;
    }
  } // From zutil.h


  var STORED_BLOCK = 0;
  var STATIC_TREES = 1;
  var DYN_TREES = 2;
  /* The three kinds of block type */

  var MIN_MATCH = 3;
  var MAX_MATCH = 258;
  /* The minimum and maximum match lengths */
  // From deflate.h

  /* ===========================================================================
   * Internal compression state.
   */

  var LENGTH_CODES = 29;
  /* number of length codes, not counting the special END_BLOCK code */

  var LITERALS = 256;
  /* number of literal bytes 0..255 */

  var L_CODES = LITERALS + 1 + LENGTH_CODES;
  /* number of Literal or Length codes, including the END_BLOCK code */

  var D_CODES = 30;
  /* number of distance codes */

  var BL_CODES = 19;
  /* number of codes used to transfer the bit lengths */

  var HEAP_SIZE = 2 * L_CODES + 1;
  /* maximum heap size */

  var MAX_BITS = 15;
  /* All codes must not exceed MAX_BITS bits */

  var Buf_size = 16;
  /* size of bit buffer in bi_buf */

  /* ===========================================================================
   * Constants
   */

  var MAX_BL_BITS = 7;
  /* Bit length codes must not exceed MAX_BL_BITS bits */

  var END_BLOCK = 256;
  /* end of block literal code */

  var REP_3_6 = 16;
  /* repeat previous bit length 3-6 times (2 bits of repeat count) */

  var REPZ_3_10 = 17;
  /* repeat a zero length 3-10 times  (3 bits of repeat count) */

  var REPZ_11_138 = 18;
  /* repeat a zero length 11-138 times  (7 bits of repeat count) */

  /* eslint-disable comma-spacing,array-bracket-spacing */

  var extra_lbits =
  /* extra bits for each length code */
  [0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0];
  var extra_dbits =
  /* extra bits for each distance code */
  [0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13];
  var extra_blbits =
  /* extra bits for each bit length code */
  [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 7];
  var bl_order = [16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15];
  /* eslint-enable comma-spacing,array-bracket-spacing */

  /* The lengths of the bit length codes are sent in order of decreasing
   * probability, to avoid transmitting the lengths for unused bit length codes.
   */

  /* ===========================================================================
   * Local data. These are initialized only once.
   */
  // We pre-fill arrays with 0 to avoid uninitialized gaps

  var DIST_CODE_LEN = 512;
  /* see definition of array dist_code below */
  // !!!! Use flat array instead of structure, Freq = i*2, Len = i*2+1

  var static_ltree = new Array((L_CODES + 2) * 2);
  zero(static_ltree);
  /* The static literal tree. Since the bit lengths are imposed, there is no
   * need for the L_CODES extra codes used during heap construction. However
   * The codes 286 and 287 are needed to build a canonical tree (see _tr_init
   * below).
   */

  var static_dtree = new Array(D_CODES * 2);
  zero(static_dtree);
  /* The static distance tree. (Actually a trivial tree since all codes use
   * 5 bits.)
   */

  var _dist_code = new Array(DIST_CODE_LEN);

  zero(_dist_code);
  /* Distance codes. The first 256 values correspond to the distances
   * 3 .. 258, the last 256 values correspond to the top 8 bits of
   * the 15 bit distances.
   */

  var _length_code = new Array(MAX_MATCH - MIN_MATCH + 1);

  zero(_length_code);
  /* length code for each normalized match length (0 == MIN_MATCH) */

  var base_length = new Array(LENGTH_CODES);
  zero(base_length);
  /* First normalized length for each code (0 = MIN_MATCH) */

  var base_dist = new Array(D_CODES);
  zero(base_dist);
  /* First normalized distance for each code (0 = distance of 1) */

  function StaticTreeDesc(static_tree, extra_bits, extra_base, elems, max_length) {
    this.static_tree = static_tree;
    /* static tree or NULL */

    this.extra_bits = extra_bits;
    /* extra bits for each code or NULL */

    this.extra_base = extra_base;
    /* base index for extra_bits */

    this.elems = elems;
    /* max number of elements in the tree */

    this.max_length = max_length;
    /* max bit length for the codes */
    // show if `static_tree` has data or dummy - needed for monomorphic objects

    this.has_stree = static_tree && static_tree.length;
  }

  var static_l_desc;
  var static_d_desc;
  var static_bl_desc;

  function TreeDesc(dyn_tree, stat_desc) {
    this.dyn_tree = dyn_tree;
    /* the dynamic tree */

    this.max_code = 0;
    /* largest code with non zero frequency */

    this.stat_desc = stat_desc;
    /* the corresponding static tree */
  }

  function d_code(dist) {
    return dist < 256 ? _dist_code[dist] : _dist_code[256 + (dist >>> 7)];
  }
  /* ===========================================================================
   * Output a short LSB first on the stream.
   * IN assertion: there is enough room in pendingBuf.
   */


  function put_short(s, w) {
    //    put_byte(s, (uch)((w) & 0xff));
    //    put_byte(s, (uch)((ush)(w) >> 8));
    s.pending_buf[s.pending++] = w & 0xff;
    s.pending_buf[s.pending++] = w >>> 8 & 0xff;
  }
  /* ===========================================================================
   * Send a value on a given number of bits.
   * IN assertion: length <= 16 and value fits in length bits.
   */


  function send_bits(s, value, length) {
    if (s.bi_valid > Buf_size - length) {
      s.bi_buf |= value << s.bi_valid & 0xffff;
      put_short(s, s.bi_buf);
      s.bi_buf = value >> Buf_size - s.bi_valid;
      s.bi_valid += length - Buf_size;
    } else {
      s.bi_buf |= value << s.bi_valid & 0xffff;
      s.bi_valid += length;
    }
  }

  function send_code(s, c, tree) {
    send_bits(s, tree[c * 2]
    /*.Code*/
    , tree[c * 2 + 1]
    /*.Len*/
    );
  }
  /* ===========================================================================
   * Reverse the first len bits of a code, using straightforward code (a faster
   * method would use a table)
   * IN assertion: 1 <= len <= 15
   */


  function bi_reverse(code, len) {
    var res = 0;

    do {
      res |= code & 1;
      code >>>= 1;
      res <<= 1;
    } while (--len > 0);

    return res >>> 1;
  }
  /* ===========================================================================
   * Flush the bit buffer, keeping at most 7 bits in it.
   */


  function bi_flush(s) {
    if (s.bi_valid === 16) {
      put_short(s, s.bi_buf);
      s.bi_buf = 0;
      s.bi_valid = 0;
    } else if (s.bi_valid >= 8) {
      s.pending_buf[s.pending++] = s.bi_buf & 0xff;
      s.bi_buf >>= 8;
      s.bi_valid -= 8;
    }
  }
  /* ===========================================================================
   * Compute the optimal bit lengths for a tree and update the total bit length
   * for the current block.
   * IN assertion: the fields freq and dad are set, heap[heap_max] and
   *    above are the tree nodes sorted by increasing frequency.
   * OUT assertions: the field len is set to the optimal bit length, the
   *     array bl_count contains the frequencies for each bit length.
   *     The length opt_len is updated; static_len is also updated if stree is
   *     not null.
   */


  function gen_bitlen(s, desc) //    deflate_state *s;
  //    tree_desc *desc;    /* the tree descriptor */
  {
    var tree = desc.dyn_tree;
    var max_code = desc.max_code;
    var stree = desc.stat_desc.static_tree;
    var has_stree = desc.stat_desc.has_stree;
    var extra = desc.stat_desc.extra_bits;
    var base = desc.stat_desc.extra_base;
    var max_length = desc.stat_desc.max_length;
    var h;
    /* heap index */

    var n, m;
    /* iterate over the tree elements */

    var bits;
    /* bit length */

    var xbits;
    /* extra bits */

    var f;
    /* frequency */

    var overflow = 0;
    /* number of elements with bit length too large */

    for (bits = 0; bits <= MAX_BITS; bits++) {
      s.bl_count[bits] = 0;
    }
    /* In a first pass, compute the optimal bit lengths (which may
     * overflow in the case of the bit length tree).
     */


    tree[s.heap[s.heap_max] * 2 + 1]
    /*.Len*/
    = 0;
    /* root of the heap */

    for (h = s.heap_max + 1; h < HEAP_SIZE; h++) {
      n = s.heap[h];
      bits = tree[tree[n * 2 + 1]
      /*.Dad*/
      * 2 + 1]
      /*.Len*/
      + 1;

      if (bits > max_length) {
        bits = max_length;
        overflow++;
      }

      tree[n * 2 + 1]
      /*.Len*/
      = bits;
      /* We overwrite tree[n].Dad which is no longer needed */

      if (n > max_code) {
        continue;
      }
      /* not a leaf node */


      s.bl_count[bits]++;
      xbits = 0;

      if (n >= base) {
        xbits = extra[n - base];
      }

      f = tree[n * 2]
      /*.Freq*/
      ;
      s.opt_len += f * (bits + xbits);

      if (has_stree) {
        s.static_len += f * (stree[n * 2 + 1]
        /*.Len*/
        + xbits);
      }
    }

    if (overflow === 0) {
      return;
    } // Trace((stderr,"\nbit length overflow\n"));

    /* This happens for example on obj2 and pic of the Calgary corpus */

    /* Find the first bit length which could increase: */


    do {
      bits = max_length - 1;

      while (s.bl_count[bits] === 0) {
        bits--;
      }

      s.bl_count[bits]--;
      /* move one leaf down the tree */

      s.bl_count[bits + 1] += 2;
      /* move one overflow item as its brother */

      s.bl_count[max_length]--;
      /* The brother of the overflow item also moves one step up,
       * but this does not affect bl_count[max_length]
       */

      overflow -= 2;
    } while (overflow > 0);
    /* Now recompute all bit lengths, scanning in increasing frequency.
     * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
     * lengths instead of fixing only the wrong ones. This idea is taken
     * from 'ar' written by Haruhiko Okumura.)
     */


    for (bits = max_length; bits !== 0; bits--) {
      n = s.bl_count[bits];

      while (n !== 0) {
        m = s.heap[--h];

        if (m > max_code) {
          continue;
        }

        if (tree[m * 2 + 1]
        /*.Len*/
        !== bits) {
          // Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
          s.opt_len += (bits - tree[m * 2 + 1]
          /*.Len*/
          ) * tree[m * 2]
          /*.Freq*/
          ;
          tree[m * 2 + 1]
          /*.Len*/
          = bits;
        }

        n--;
      }
    }
  }
  /* ===========================================================================
   * Generate the codes for a given tree and bit counts (which need not be
   * optimal).
   * IN assertion: the array bl_count contains the bit length statistics for
   * the given tree and the field len is set for all tree elements.
   * OUT assertion: the field code is set for all tree elements of non
   *     zero code length.
   */


  function gen_codes(tree, max_code, bl_count) //    ct_data *tree;             /* the tree to decorate */
  //    int max_code;              /* largest code with non zero frequency */
  //    ushf *bl_count;            /* number of codes at each bit length */
  {
    var next_code = new Array(MAX_BITS + 1);
    /* next code value for each bit length */

    var code = 0;
    /* running code value */

    var bits;
    /* bit index */

    var n;
    /* code index */

    /* The distribution counts are first used to generate the code values
     * without bit reversal.
     */

    for (bits = 1; bits <= MAX_BITS; bits++) {
      next_code[bits] = code = code + bl_count[bits - 1] << 1;
    }
    /* Check that the bit counts in bl_count are consistent. The last code
     * must be all ones.
     */
    //Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
    //        "inconsistent bit counts");
    //Tracev((stderr,"\ngen_codes: max_code %d ", max_code));


    for (n = 0; n <= max_code; n++) {
      var len = tree[n * 2 + 1]
      /*.Len*/
      ;

      if (len === 0) {
        continue;
      }
      /* Now reverse the bits */


      tree[n * 2]
      /*.Code*/
      = bi_reverse(next_code[len]++, len); //Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
      //     n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
    }
  }
  /* ===========================================================================
   * Initialize the various 'constant' tables.
   */


  function tr_static_init() {
    var n;
    /* iterates over tree elements */

    var bits;
    /* bit counter */

    var length;
    /* length value */

    var code;
    /* code value */

    var dist;
    /* distance index */

    var bl_count = new Array(MAX_BITS + 1);
    /* number of codes at each bit length for an optimal tree */
    // do check in _tr_init()
    //if (static_init_done) return;

    /* For some embedded targets, global variables are not initialized: */

    /*#ifdef NO_INIT_GLOBAL_POINTERS
      static_l_desc.static_tree = static_ltree;
      static_l_desc.extra_bits = extra_lbits;
      static_d_desc.static_tree = static_dtree;
      static_d_desc.extra_bits = extra_dbits;
      static_bl_desc.extra_bits = extra_blbits;
    #endif*/

    /* Initialize the mapping length (0..255) -> length code (0..28) */

    length = 0;

    for (code = 0; code < LENGTH_CODES - 1; code++) {
      base_length[code] = length;

      for (n = 0; n < 1 << extra_lbits[code]; n++) {
        _length_code[length++] = code;
      }
    } //Assert (length == 256, "tr_static_init: length != 256");

    /* Note that the length 255 (match length 258) can be represented
     * in two different ways: code 284 + 5 bits or code 285, so we
     * overwrite length_code[255] to use the best encoding:
     */


    _length_code[length - 1] = code;
    /* Initialize the mapping dist (0..32K) -> dist code (0..29) */

    dist = 0;

    for (code = 0; code < 16; code++) {
      base_dist[code] = dist;

      for (n = 0; n < 1 << extra_dbits[code]; n++) {
        _dist_code[dist++] = code;
      }
    } //Assert (dist == 256, "tr_static_init: dist != 256");


    dist >>= 7;
    /* from now on, all distances are divided by 128 */

    for (; code < D_CODES; code++) {
      base_dist[code] = dist << 7;

      for (n = 0; n < 1 << extra_dbits[code] - 7; n++) {
        _dist_code[256 + dist++] = code;
      }
    } //Assert (dist == 256, "tr_static_init: 256+dist != 512");

    /* Construct the codes of the static literal tree */


    for (bits = 0; bits <= MAX_BITS; bits++) {
      bl_count[bits] = 0;
    }

    n = 0;

    while (n <= 143) {
      static_ltree[n * 2 + 1]
      /*.Len*/
      = 8;
      n++;
      bl_count[8]++;
    }

    while (n <= 255) {
      static_ltree[n * 2 + 1]
      /*.Len*/
      = 9;
      n++;
      bl_count[9]++;
    }

    while (n <= 279) {
      static_ltree[n * 2 + 1]
      /*.Len*/
      = 7;
      n++;
      bl_count[7]++;
    }

    while (n <= 287) {
      static_ltree[n * 2 + 1]
      /*.Len*/
      = 8;
      n++;
      bl_count[8]++;
    }
    /* Codes 286 and 287 do not exist, but we must include them in the
     * tree construction to get a canonical Huffman tree (longest code
     * all ones)
     */


    gen_codes(static_ltree, L_CODES + 1, bl_count);
    /* The static distance tree is trivial: */

    for (n = 0; n < D_CODES; n++) {
      static_dtree[n * 2 + 1]
      /*.Len*/
      = 5;
      static_dtree[n * 2]
      /*.Code*/
      = bi_reverse(n, 5);
    } // Now data ready and we can init static trees


    static_l_desc = new StaticTreeDesc(static_ltree, extra_lbits, LITERALS + 1, L_CODES, MAX_BITS);
    static_d_desc = new StaticTreeDesc(static_dtree, extra_dbits, 0, D_CODES, MAX_BITS);
    static_bl_desc = new StaticTreeDesc(new Array(0), extra_blbits, 0, BL_CODES, MAX_BL_BITS); //static_init_done = true;
  }
  /* ===========================================================================
   * Initialize a new block.
   */


  function init_block(s) {
    var n;
    /* iterates over tree elements */

    /* Initialize the trees. */

    for (n = 0; n < L_CODES; n++) {
      s.dyn_ltree[n * 2]
      /*.Freq*/
      = 0;
    }

    for (n = 0; n < D_CODES; n++) {
      s.dyn_dtree[n * 2]
      /*.Freq*/
      = 0;
    }

    for (n = 0; n < BL_CODES; n++) {
      s.bl_tree[n * 2]
      /*.Freq*/
      = 0;
    }

    s.dyn_ltree[END_BLOCK * 2]
    /*.Freq*/
    = 1;
    s.opt_len = s.static_len = 0;
    s.last_lit = s.matches = 0;
  }
  /* ===========================================================================
   * Flush the bit buffer and align the output on a byte boundary
   */


  function bi_windup(s) {
    if (s.bi_valid > 8) {
      put_short(s, s.bi_buf);
    } else if (s.bi_valid > 0) {
      //put_byte(s, (Byte)s->bi_buf);
      s.pending_buf[s.pending++] = s.bi_buf;
    }

    s.bi_buf = 0;
    s.bi_valid = 0;
  }
  /* ===========================================================================
   * Copy a stored block, storing first the length and its
   * one's complement if requested.
   */


  function copy_block(s, buf, len, header) //DeflateState *s;
  //charf    *buf;    /* the input data */
  //unsigned len;     /* its length */
  //int      header;  /* true if block header must be written */
  {
    bi_windup(s);
    /* align on byte boundary */

    if (header) {
      put_short(s, len);
      put_short(s, ~len);
    } //  while (len--) {
    //    put_byte(s, *buf++);
    //  }


    utils.arraySet(s.pending_buf, s.window, buf, len, s.pending);
    s.pending += len;
  }
  /* ===========================================================================
   * Compares to subtrees, using the tree depth as tie breaker when
   * the subtrees have equal frequency. This minimizes the worst case length.
   */


  function smaller(tree, n, m, depth) {
    var _n2 = n * 2;

    var _m2 = m * 2;

    return tree[_n2]
    /*.Freq*/
    < tree[_m2]
    /*.Freq*/
    || tree[_n2]
    /*.Freq*/
    === tree[_m2]
    /*.Freq*/
    && depth[n] <= depth[m];
  }
  /* ===========================================================================
   * Restore the heap property by moving down the tree starting at node k,
   * exchanging a node with the smallest of its two sons if necessary, stopping
   * when the heap property is re-established (each father smaller than its
   * two sons).
   */


  function pqdownheap(s, tree, k) //    deflate_state *s;
  //    ct_data *tree;  /* the tree to restore */
  //    int k;               /* node to move down */
  {
    var v = s.heap[k];
    var j = k << 1;
    /* left son of k */

    while (j <= s.heap_len) {
      /* Set j to the smallest of the two sons: */
      if (j < s.heap_len && smaller(tree, s.heap[j + 1], s.heap[j], s.depth)) {
        j++;
      }
      /* Exit if v is smaller than both sons */


      if (smaller(tree, v, s.heap[j], s.depth)) {
        break;
      }
      /* Exchange v with the smallest son */


      s.heap[k] = s.heap[j];
      k = j;
      /* And continue down the tree, setting j to the left son of k */

      j <<= 1;
    }

    s.heap[k] = v;
  } // inlined manually
  // var SMALLEST = 1;

  /* ===========================================================================
   * Send the block data compressed using the given Huffman trees
   */


  function compress_block(s, ltree, dtree) //    deflate_state *s;
  //    const ct_data *ltree; /* literal tree */
  //    const ct_data *dtree; /* distance tree */
  {
    var dist;
    /* distance of matched string */

    var lc;
    /* match length or unmatched char (if dist == 0) */

    var lx = 0;
    /* running index in l_buf */

    var code;
    /* the code to send */

    var extra;
    /* number of extra bits to send */

    if (s.last_lit !== 0) {
      do {
        dist = s.pending_buf[s.d_buf + lx * 2] << 8 | s.pending_buf[s.d_buf + lx * 2 + 1];
        lc = s.pending_buf[s.l_buf + lx];
        lx++;

        if (dist === 0) {
          send_code(s, lc, ltree);
          /* send a literal byte */
          //Tracecv(isgraph(lc), (stderr," '%c' ", lc));
        } else {
          /* Here, lc is the match length - MIN_MATCH */
          code = _length_code[lc];
          send_code(s, code + LITERALS + 1, ltree);
          /* send the length code */

          extra = extra_lbits[code];

          if (extra !== 0) {
            lc -= base_length[code];
            send_bits(s, lc, extra);
            /* send the extra length bits */
          }

          dist--;
          /* dist is now the match distance - 1 */

          code = d_code(dist); //Assert (code < D_CODES, "bad d_code");

          send_code(s, code, dtree);
          /* send the distance code */

          extra = extra_dbits[code];

          if (extra !== 0) {
            dist -= base_dist[code];
            send_bits(s, dist, extra);
            /* send the extra distance bits */
          }
        }
        /* literal or match pair ? */

        /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
        //Assert((uInt)(s->pending) < s->lit_bufsize + 2*lx,
        //       "pendingBuf overflow");

      } while (lx < s.last_lit);
    }

    send_code(s, END_BLOCK, ltree);
  }
  /* ===========================================================================
   * Construct one Huffman tree and assigns the code bit strings and lengths.
   * Update the total bit length for the current block.
   * IN assertion: the field freq is set for all tree elements.
   * OUT assertions: the fields len and code are set to the optimal bit length
   *     and corresponding code. The length opt_len is updated; static_len is
   *     also updated if stree is not null. The field max_code is set.
   */


  function build_tree(s, desc) //    deflate_state *s;
  //    tree_desc *desc; /* the tree descriptor */
  {
    var tree = desc.dyn_tree;
    var stree = desc.stat_desc.static_tree;
    var has_stree = desc.stat_desc.has_stree;
    var elems = desc.stat_desc.elems;
    var n, m;
    /* iterate over heap elements */

    var max_code = -1;
    /* largest code with non zero frequency */

    var node;
    /* new node being created */

    /* Construct the initial heap, with least frequent element in
     * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
     * heap[0] is not used.
     */

    s.heap_len = 0;
    s.heap_max = HEAP_SIZE;

    for (n = 0; n < elems; n++) {
      if (tree[n * 2]
      /*.Freq*/
      !== 0) {
        s.heap[++s.heap_len] = max_code = n;
        s.depth[n] = 0;
      } else {
        tree[n * 2 + 1]
        /*.Len*/
        = 0;
      }
    }
    /* The pkzip format requires that at least one distance code exists,
     * and that at least one bit should be sent even if there is only one
     * possible code. So to avoid special checks later on we force at least
     * two codes of non zero frequency.
     */


    while (s.heap_len < 2) {
      node = s.heap[++s.heap_len] = max_code < 2 ? ++max_code : 0;
      tree[node * 2]
      /*.Freq*/
      = 1;
      s.depth[node] = 0;
      s.opt_len--;

      if (has_stree) {
        s.static_len -= stree[node * 2 + 1]
        /*.Len*/
        ;
      }
      /* node is 0 or 1 so it does not have extra bits */

    }

    desc.max_code = max_code;
    /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
     * establish sub-heaps of increasing lengths:
     */

    for (n = s.heap_len >> 1
    /*int /2*/
    ; n >= 1; n--) {
      pqdownheap(s, tree, n);
    }
    /* Construct the Huffman tree by repeatedly combining the least two
     * frequent nodes.
     */


    node = elems;
    /* next internal node of the tree */

    do {
      //pqremove(s, tree, n);  /* n = node of least frequency */

      /*** pqremove ***/
      n = s.heap[1
      /*SMALLEST*/
      ];
      s.heap[1
      /*SMALLEST*/
      ] = s.heap[s.heap_len--];
      pqdownheap(s, tree, 1
      /*SMALLEST*/
      );
      /***/

      m = s.heap[1
      /*SMALLEST*/
      ];
      /* m = node of next least frequency */

      s.heap[--s.heap_max] = n;
      /* keep the nodes sorted by frequency */

      s.heap[--s.heap_max] = m;
      /* Create a new node father of n and m */

      tree[node * 2]
      /*.Freq*/
      = tree[n * 2]
      /*.Freq*/
      + tree[m * 2]
      /*.Freq*/
      ;
      s.depth[node] = (s.depth[n] >= s.depth[m] ? s.depth[n] : s.depth[m]) + 1;
      tree[n * 2 + 1]
      /*.Dad*/
      = tree[m * 2 + 1]
      /*.Dad*/
      = node;
      /* and insert the new node in the heap */

      s.heap[1
      /*SMALLEST*/
      ] = node++;
      pqdownheap(s, tree, 1
      /*SMALLEST*/
      );
    } while (s.heap_len >= 2);

    s.heap[--s.heap_max] = s.heap[1
    /*SMALLEST*/
    ];
    /* At this point, the fields freq and dad are set. We can now
     * generate the bit lengths.
     */

    gen_bitlen(s, desc);
    /* The field len is now set, we can generate the bit codes */

    gen_codes(tree, max_code, s.bl_count);
  }
  /* ===========================================================================
   * Scan a literal or distance tree to determine the frequencies of the codes
   * in the bit length tree.
   */


  function scan_tree(s, tree, max_code) //    deflate_state *s;
  //    ct_data *tree;   /* the tree to be scanned */
  //    int max_code;    /* and its largest code of non zero frequency */
  {
    var n;
    /* iterates over all tree elements */

    var prevlen = -1;
    /* last emitted length */

    var curlen;
    /* length of current code */

    var nextlen = tree[0 * 2 + 1]
    /*.Len*/
    ;
    /* length of next code */

    var count = 0;
    /* repeat count of the current code */

    var max_count = 7;
    /* max repeat count */

    var min_count = 4;
    /* min repeat count */

    if (nextlen === 0) {
      max_count = 138;
      min_count = 3;
    }

    tree[(max_code + 1) * 2 + 1]
    /*.Len*/
    = 0xffff;
    /* guard */

    for (n = 0; n <= max_code; n++) {
      curlen = nextlen;
      nextlen = tree[(n + 1) * 2 + 1]
      /*.Len*/
      ;

      if (++count < max_count && curlen === nextlen) {
        continue;
      } else if (count < min_count) {
        s.bl_tree[curlen * 2]
        /*.Freq*/
        += count;
      } else if (curlen !== 0) {
        if (curlen !== prevlen) {
          s.bl_tree[curlen * 2] /*.Freq*/++;
        }

        s.bl_tree[REP_3_6 * 2] /*.Freq*/++;
      } else if (count <= 10) {
        s.bl_tree[REPZ_3_10 * 2] /*.Freq*/++;
      } else {
        s.bl_tree[REPZ_11_138 * 2] /*.Freq*/++;
      }

      count = 0;
      prevlen = curlen;

      if (nextlen === 0) {
        max_count = 138;
        min_count = 3;
      } else if (curlen === nextlen) {
        max_count = 6;
        min_count = 3;
      } else {
        max_count = 7;
        min_count = 4;
      }
    }
  }
  /* ===========================================================================
   * Send a literal or distance tree in compressed form, using the codes in
   * bl_tree.
   */


  function send_tree(s, tree, max_code) //    deflate_state *s;
  //    ct_data *tree; /* the tree to be scanned */
  //    int max_code;       /* and its largest code of non zero frequency */
  {
    var n;
    /* iterates over all tree elements */

    var prevlen = -1;
    /* last emitted length */

    var curlen;
    /* length of current code */

    var nextlen = tree[0 * 2 + 1]
    /*.Len*/
    ;
    /* length of next code */

    var count = 0;
    /* repeat count of the current code */

    var max_count = 7;
    /* max repeat count */

    var min_count = 4;
    /* min repeat count */

    /* tree[max_code+1].Len = -1; */

    /* guard already set */

    if (nextlen === 0) {
      max_count = 138;
      min_count = 3;
    }

    for (n = 0; n <= max_code; n++) {
      curlen = nextlen;
      nextlen = tree[(n + 1) * 2 + 1]
      /*.Len*/
      ;

      if (++count < max_count && curlen === nextlen) {
        continue;
      } else if (count < min_count) {
        do {
          send_code(s, curlen, s.bl_tree);
        } while (--count !== 0);
      } else if (curlen !== 0) {
        if (curlen !== prevlen) {
          send_code(s, curlen, s.bl_tree);
          count--;
        } //Assert(count >= 3 && count <= 6, " 3_6?");


        send_code(s, REP_3_6, s.bl_tree);
        send_bits(s, count - 3, 2);
      } else if (count <= 10) {
        send_code(s, REPZ_3_10, s.bl_tree);
        send_bits(s, count - 3, 3);
      } else {
        send_code(s, REPZ_11_138, s.bl_tree);
        send_bits(s, count - 11, 7);
      }

      count = 0;
      prevlen = curlen;

      if (nextlen === 0) {
        max_count = 138;
        min_count = 3;
      } else if (curlen === nextlen) {
        max_count = 6;
        min_count = 3;
      } else {
        max_count = 7;
        min_count = 4;
      }
    }
  }
  /* ===========================================================================
   * Construct the Huffman tree for the bit lengths and return the index in
   * bl_order of the last bit length code to send.
   */


  function build_bl_tree(s) {
    var max_blindex;
    /* index of last bit length code of non zero freq */

    /* Determine the bit length frequencies for literal and distance trees */

    scan_tree(s, s.dyn_ltree, s.l_desc.max_code);
    scan_tree(s, s.dyn_dtree, s.d_desc.max_code);
    /* Build the bit length tree: */

    build_tree(s, s.bl_desc);
    /* opt_len now includes the length of the tree representations, except
     * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
     */

    /* Determine the number of bit length codes to send. The pkzip format
     * requires that at least 4 bit length codes be sent. (appnote.txt says
     * 3 but the actual value used is 4.)
     */

    for (max_blindex = BL_CODES - 1; max_blindex >= 3; max_blindex--) {
      if (s.bl_tree[bl_order[max_blindex] * 2 + 1]
      /*.Len*/
      !== 0) {
        break;
      }
    }
    /* Update opt_len to include the bit length tree and counts */


    s.opt_len += 3 * (max_blindex + 1) + 5 + 5 + 4; //Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
    //        s->opt_len, s->static_len));

    return max_blindex;
  }
  /* ===========================================================================
   * Send the header for a block using dynamic Huffman trees: the counts, the
   * lengths of the bit length codes, the literal tree and the distance tree.
   * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
   */


  function send_all_trees(s, lcodes, dcodes, blcodes) //    deflate_state *s;
  //    int lcodes, dcodes, blcodes; /* number of codes for each tree */
  {
    var rank;
    /* index in bl_order */
    //Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
    //Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
    //        "too many codes");
    //Tracev((stderr, "\nbl counts: "));

    send_bits(s, lcodes - 257, 5);
    /* not +255 as stated in appnote.txt */

    send_bits(s, dcodes - 1, 5);
    send_bits(s, blcodes - 4, 4);
    /* not -3 as stated in appnote.txt */

    for (rank = 0; rank < blcodes; rank++) {
      //Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
      send_bits(s, s.bl_tree[bl_order[rank] * 2 + 1]
      /*.Len*/
      , 3);
    } //Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));


    send_tree(s, s.dyn_ltree, lcodes - 1);
    /* literal tree */
    //Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));

    send_tree(s, s.dyn_dtree, dcodes - 1);
    /* distance tree */
    //Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
  }
  /* ===========================================================================
   * Check if the data type is TEXT or BINARY, using the following algorithm:
   * - TEXT if the two conditions below are satisfied:
   *    a) There are no non-portable control characters belonging to the
   *       "black list" (0..6, 14..25, 28..31).
   *    b) There is at least one printable character belonging to the
   *       "white list" (9 {TAB}, 10 {LF}, 13 {CR}, 32..255).
   * - BINARY otherwise.
   * - The following partially-portable control characters form a
   *   "gray list" that is ignored in this detection algorithm:
   *   (7 {BEL}, 8 {BS}, 11 {VT}, 12 {FF}, 26 {SUB}, 27 {ESC}).
   * IN assertion: the fields Freq of dyn_ltree are set.
   */


  function detect_data_type(s) {
    /* black_mask is the bit mask of black-listed bytes
     * set bits 0..6, 14..25, and 28..31
     * 0xf3ffc07f = binary 11110011111111111100000001111111
     */
    var black_mask = 0xf3ffc07f;
    var n;
    /* Check for non-textual ("black-listed") bytes. */

    for (n = 0; n <= 31; n++, black_mask >>>= 1) {
      if (black_mask & 1 && s.dyn_ltree[n * 2]
      /*.Freq*/
      !== 0) {
        return Z_BINARY;
      }
    }
    /* Check for textual ("white-listed") bytes. */


    if (s.dyn_ltree[9 * 2]
    /*.Freq*/
    !== 0 || s.dyn_ltree[10 * 2]
    /*.Freq*/
    !== 0 || s.dyn_ltree[13 * 2]
    /*.Freq*/
    !== 0) {
      return Z_TEXT;
    }

    for (n = 32; n < LITERALS; n++) {
      if (s.dyn_ltree[n * 2]
      /*.Freq*/
      !== 0) {
        return Z_TEXT;
      }
    }
    /* There are no "black-listed" or "white-listed" bytes:
     * this stream either is empty or has tolerated ("gray-listed") bytes only.
     */


    return Z_BINARY;
  }

  var static_init_done = false;
  /* ===========================================================================
   * Initialize the tree data structures for a new zlib stream.
   */

  function _tr_init(s) {
    if (!static_init_done) {
      tr_static_init();
      static_init_done = true;
    }

    s.l_desc = new TreeDesc(s.dyn_ltree, static_l_desc);
    s.d_desc = new TreeDesc(s.dyn_dtree, static_d_desc);
    s.bl_desc = new TreeDesc(s.bl_tree, static_bl_desc);
    s.bi_buf = 0;
    s.bi_valid = 0;
    /* Initialize the first block of the first file: */

    init_block(s);
  }
  /* ===========================================================================
   * Send a stored block
   */


  function _tr_stored_block(s, buf, stored_len, last) //DeflateState *s;
  //charf *buf;       /* input block */
  //ulg stored_len;   /* length of input block */
  //int last;         /* one if this is the last block for a file */
  {
    send_bits(s, (STORED_BLOCK << 1) + (last ? 1 : 0), 3);
    /* send block type */

    copy_block(s, buf, stored_len, true);
    /* with header */
  }
  /* ===========================================================================
   * Send one empty static block to give enough lookahead for inflate.
   * This takes 10 bits, of which 7 may remain in the bit buffer.
   */


  function _tr_align(s) {
    send_bits(s, STATIC_TREES << 1, 3);
    send_code(s, END_BLOCK, static_ltree);
    bi_flush(s);
  }
  /* ===========================================================================
   * Determine the best encoding for the current block: dynamic trees, static
   * trees or store, and output the encoded block to the zip file.
   */


  function _tr_flush_block(s, buf, stored_len, last) //DeflateState *s;
  //charf *buf;       /* input block, or NULL if too old */
  //ulg stored_len;   /* length of input block */
  //int last;         /* one if this is the last block for a file */
  {
    var opt_lenb, static_lenb;
    /* opt_len and static_len in bytes */

    var max_blindex = 0;
    /* index of last bit length code of non zero freq */

    /* Build the Huffman trees unless a stored block is forced */

    if (s.level > 0) {
      /* Check if the file is binary or text */
      if (s.strm.data_type === Z_UNKNOWN) {
        s.strm.data_type = detect_data_type(s);
      }
      /* Construct the literal and distance trees */


      build_tree(s, s.l_desc); // Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
      //        s->static_len));

      build_tree(s, s.d_desc); // Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
      //        s->static_len));

      /* At this point, opt_len and static_len are the total bit lengths of
       * the compressed block data, excluding the tree representations.
       */

      /* Build the bit length tree for the above two trees, and get the index
       * in bl_order of the last bit length code to send.
       */

      max_blindex = build_bl_tree(s);
      /* Determine the best encoding. Compute the block lengths in bytes. */

      opt_lenb = s.opt_len + 3 + 7 >>> 3;
      static_lenb = s.static_len + 3 + 7 >>> 3; // Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
      //        opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
      //        s->last_lit));

      if (static_lenb <= opt_lenb) {
        opt_lenb = static_lenb;
      }
    } else {
      // Assert(buf != (char*)0, "lost buf");
      opt_lenb = static_lenb = stored_len + 5;
      /* force a stored block */
    }

    if (stored_len + 4 <= opt_lenb && buf !== -1) {
      /* 4: two words for the lengths */

      /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
       * Otherwise we can't have processed more than WSIZE input bytes since
       * the last block flush, because compression would have been
       * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
       * transform a block into a stored block.
       */
      _tr_stored_block(s, buf, stored_len, last);
    } else if (s.strategy === Z_FIXED || static_lenb === opt_lenb) {
      send_bits(s, (STATIC_TREES << 1) + (last ? 1 : 0), 3);
      compress_block(s, static_ltree, static_dtree);
    } else {
      send_bits(s, (DYN_TREES << 1) + (last ? 1 : 0), 3);
      send_all_trees(s, s.l_desc.max_code + 1, s.d_desc.max_code + 1, max_blindex + 1);
      compress_block(s, s.dyn_ltree, s.dyn_dtree);
    } // Assert (s->compressed_len == s->bits_sent, "bad compressed size");

    /* The above check is made mod 2^32, for files larger than 512 MB
     * and uLong implemented on 32 bits.
     */


    init_block(s);

    if (last) {
      bi_windup(s);
    } // Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
    //       s->compressed_len-7*last));

  }
  /* ===========================================================================
   * Save the match info and tally the frequency counts. Return true if
   * the current block must be flushed.
   */


  function _tr_tally(s, dist, lc) //    deflate_state *s;
  //    unsigned dist;  /* distance of matched string */
  //    unsigned lc;    /* match length-MIN_MATCH or unmatched char (if dist==0) */
  {
    //var out_length, in_length, dcode;
    s.pending_buf[s.d_buf + s.last_lit * 2] = dist >>> 8 & 0xff;
    s.pending_buf[s.d_buf + s.last_lit * 2 + 1] = dist & 0xff;
    s.pending_buf[s.l_buf + s.last_lit] = lc & 0xff;
    s.last_lit++;

    if (dist === 0) {
      /* lc is the unmatched char */
      s.dyn_ltree[lc * 2] /*.Freq*/++;
    } else {
      s.matches++;
      /* Here, lc is the match length - MIN_MATCH */

      dist--;
      /* dist = match distance - 1 */
      //Assert((ush)dist < (ush)MAX_DIST(s) &&
      //       (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
      //       (ush)d_code(dist) < (ush)D_CODES,  "_tr_tally: bad match");

      s.dyn_ltree[(_length_code[lc] + LITERALS + 1) * 2] /*.Freq*/++;
      s.dyn_dtree[d_code(dist) * 2] /*.Freq*/++;
    } // (!) This block is disabled in zlib defaults,
    // don't enable it for binary compatibility
    //#ifdef TRUNCATE_BLOCK
    //  /* Try to guess if it is profitable to stop the current block here */
    //  if ((s.last_lit & 0x1fff) === 0 && s.level > 2) {
    //    /* Compute an upper bound for the compressed length */
    //    out_length = s.last_lit*8;
    //    in_length = s.strstart - s.block_start;
    //
    //    for (dcode = 0; dcode < D_CODES; dcode++) {
    //      out_length += s.dyn_dtree[dcode*2]/*.Freq*/ * (5 + extra_dbits[dcode]);
    //    }
    //    out_length >>>= 3;
    //    //Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
    //    //       s->last_lit, in_length, out_length,
    //    //       100L - out_length*100L/in_length));
    //    if (s.matches < (s.last_lit>>1)/*int /2*/ && out_length < (in_length>>1)/*int /2*/) {
    //      return true;
    //    }
    //  }
    //#endif


    return s.last_lit === s.lit_bufsize - 1;
    /* We avoid equality with lit_bufsize because of wraparound at 64K
     * on 16 bit machines and because stored blocks are restricted to
     * 64K-1 bytes.
     */
  }

  exports._tr_init = _tr_init;
  exports._tr_stored_block = _tr_stored_block;
  exports._tr_flush_block = _tr_flush_block;
  exports._tr_tally = _tr_tally;
  exports._tr_align = _tr_align;
  return exports;
}